In recent years, there have been an increasing number of opportunities at which video contents are viewed on displays for personal computers, which have resolutions exceeding the resolution of the standard-resolution video (Standard Definition (SD) video: 480×480˜720×480). In addition, with the full-scale implementation of Hi-Vision broadcast, television receivers, which are adaptive to sub-high-resolution video (1440×1080) and high-resolution video (Full High Definition (full HD) video: 1920×1080), have been prevailing in home. Accordingly, up-convert techniques have been proposed for converting SD video, such as DVD video, or quasi-high-resolution video of, e.g. terrestrial digital broadcast, to high-resolution video.
Jpn. Pat. Appln. KOKAI Publication No. 2001-189851 discloses an image processing apparatus which can obtain a high image-quality image without an interpolation blur or jaggy, when a low-resolution image is converted to a high-resolution image. According to this image processing apparatus, even if an artificially created character/line image and a natural image are mixed in an image, it is possible to generate an image in which edges of the character/line image portion are reproduced and an interpolation blur in the natural image portion is suppressed.
In the meantime, an imaging blur due to the characteristics of an imaging device, a lens, etc., may occur in a video captured by using a video camera. To cope with this problem, there has been proposed an image quality processing technique for suppressing an imaging blur by subjecting the captured video to an image quality enhancing process which uses a point spread function (PSF) as an imaging model function.
However, the video content of, e.g. a television broadcast program includes videos which are different in characteristic. For example, a captured video and a graphics video such as an animation or a computer graphics are present. No imaging blur occurs in the graphics video. Thus, if the image quality enhancing process using the PSF is executed on the graphics video contents, degradation may occur in the image quality of the graphics video contents.